Starting-rheostat.



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(ff/M i@ raul. u; ZIMMER, OF s'cHENEcTADY, New YORK, AssIGNOR Y, .PANY,A CORPORATION OF NEW To all whom it may concern:

Bc itlrnown that To GENERAL ELECTRIC GOM- YORK.

srnnrme-nnnos'ra'r.

Naciones.

Speccation of Letters Patent.

vintermedi:.april 2?, 1909.

Application led December 26, 1967. Sera No. 408,146.

I, PAUL H. ZIMMER, a

",citizen `of the United States, residing at Schenectady, countyy ofSchenectady, State or' New York, have'rinvented certain new und' usefulImprovements l fica( ion.`

y character which cannot l careless handling of the operator,

This invention'relates to devices for controlling electri'cinotorcircuits and has for its Object the provision of a device of this bedestroyed by the und which is, at the same time, simple'incoifietruction in addition to being extremelyy i, reliable, eicient anddurable.

lily invention relatesmore specifically to inotor" starting' rheostats.vIn y devices of this character itis. common tov start theiu'otorbymoving thev lcontrolling arm over contuct'studs until therio-voltage' magnet is rcucl1ed,=the inoto'r circuit` being closed uponx 4of overload conditions;'and a separate, in- .l dependently4 actuatedswitch, energized upon i .the initial movement ntlielcircuit. ,40

v so that the?. circuit will it is unnecessary I* be biased to the thefirst contact stud. With this arrangel ment, upon the failure ofvoltage, the arm returns to thestarting position and the circuit willbe. opened upon the first stud,

Y(hereby causing arcing' and burning of thel Vcontact studs.

OneOfftheobjectsfofvmy invention is to provide, inA combination with anelectroniagneticrswitch for closingthe main circuit, means formechanically closingthe` same before thev resistance is varied; meansfor opening thejswitch upon the occurrence n the arm is left-inanyvother than the full running position'.

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ln,` the accompanying drawing, in whichl have shown my inventionembodied in concrete form, Figurel Vis a. plan lView of my ,l devicepartly broken away showing the circuit connections, and Fig. 2 is adetail view of the operating handleand switch.

in y Starting- ,ltheostata of which the following is a specior by the' Yoccurrence of abnormal circuitconditions, l5

.be engaged byV the plunger 27 Thisf'latter switch is arranged Referringto the drawings, represents an insulating base of slate or soapston'eprovided With a series of contact studs 11 forining terininals'ofstarting Vresistance 12. A

`controlling arm 13 is pivoted at 14 so that its free end engages thecontact studs 11, to Vary the resistance in the usual `way.v The arm isprovided with-a handle 14' havingr a contacting plunger 15 arranged torecipro cate therein, and biased to an outward position by means of aspring 16. This plunger is adapted to engage a contact segment 17-arranged concentrically 'with the Ystuds 11. Contact between plunger andsegment is inadewhen pressure is appliedto the plunger so as to overcomethe tensionV of the spring 16 and force the end of the plungerv segment..Whom however, 'the full running position is into engagement with thereached, -the plunger is forced upwardby meansl of an odset- 18, .whichrholds .the

plunger andsegment in permanentcontact.

A switch arm 19 is pivoted concentrically with the arm 13 and isarranged to close the mainA circuit through carbon contactsl 20 and alaminatedlconiect 2l engaging the fired contact 22. The switch is biasedor spring-pressed to an Open position by means of a spring 23, While alatch 24 pivoted at 25 is spring-pressed over vapin l26- on the switcharm, and locks the sainein plecef- The free end of the latch 2,4 isarranged to of the overload magnet 28 so that, as the plunger' rises tovtrip the latch, Ait releases' the switch arm 19 to open the'inain'circuiti A solenoid switch 29 is mounted conveniently u on the base andisA provided with two windings 30 und 31,v operating` upon the core orplunger 32, cari-ying at its lower end a laminated brush Contact 33fixed contacts '3,4 raised.I This switch is 4also provided lwith carboncontacts 36 for taking the'inal break of the circuit. The winding 31 isenergized through a iixed contact 37 arrangedto be engaged by contact38, `mounted upon but arranged to, bridge the is inA its starting;Vposition. The arm 13 lis provided with a shoulder 39 adapted to .engagethe arm 19 and force it to a closed osition when the arm 13 is .moved tothe eft of its starting position on the first-of the studs 11. kMovementto the leftl is opposed and 35 when .the core is insulated from the arm13, when the latter by a spring plunger 40 which returns the arm to thestarting4 'osition. This plunger is connected to the circuit so as to-energize winding 31 when it is bridged to stud 37 by contact 38. 2

The arrangement of circuits and mode of operation are as follows; Whenit is desired to start the mtorhthe arm' 13 is moved to the' left in acounter-,clockwise direction. When the arm reaches the startingposition, contact 37 is engaged by contact 38, and the winding 31, whichis a lifting winding, is energized from the positive main throughconductor 41, conductor 42, stud 37, plunger 40, conductor 43 andl backto line. At the same time, by forcingl the arm'13 to the left, theswitch arm 19 is latched to a closed position, whereupon, the-mainarmaturecircuit is closed `at this switch. At the same time, thearmature circuit'is closed' at the contacts 34 and 35 by the energizing.of the coil 31. As the arm is moved to cutout resistance, the circuit ofwinding 3.1 will be broken at contact 37, but the circuit of the holdingcoil 30 has been energized by the operator forcing the plunger 15 .intocontact with the segment 17, so that the circuit will be kept closed atcontacts 34 and 35.` If the operator should attempt to leave the arm inany position other than the full runningir position, the circuit of thewinding 30 will immediatelyA open and thereby open the main circuit.When, however, the running position is reached, the offset 18 maintainsthe coil 30 energized. Upon the occurrence of an overload the core 27will trip the 'latch 24 and allow the switch arm 19 to open the maincircuit while the coil 30 acts as an underload coil to open thecircuitupon the failure of voltage. In this way the rheostat is protectedagainst careless handling of the operator, since the arm must always be"brought to starting position before the circuitcan be closed, while' itcannot be left in lany other than the running position with the circuitclosed.

While I have described my invention in connection with a particularmechanism and arrangement of circuits, it should be understood that I donot limit my invention in t-hese articulars, except in so far as it. islimited) by the scope of theclaims annexed hereto.

What I claim as new and desire to secure by Letters Patent of theUnitedStates, is,-.

and means whereby one ot said switches is closed mechanically and theother electro@ magnetically uponan initial movement of said arm. l

3. A starting rheostat'comprising a resistance varying arm, a plurali'.of independently actuated switches in series therewith, means forclosing said switches upon an initial movement of said arm, and meanswhereby said switches are opened upon the occurrence of no-voltage andoverload conditions, respectively.

4. A starting rheostat comprising` a resistance varying arm, a pluralityof independently actuated switches in series therewith, means wherebyone of said switches is closed mechanically and the otherelectromagnetically upon an initial movement of said arm, and meanswhereby Isaid switches are opened upon the occurrence of no-Volt-age andoverload conditions, respectively.

5. A starting rheostat comprising a resistance varying arm, a pluralityof independently actuated switches in series therewith, means wherebysaid switches are closed by an initial movement of said arm, and anormally open circuit closing' device in connection with said arm l'orcontrolling one of said switches.

6. .l starting rheostat comprising a resistance varyingl arm. aplurality of independently actuated switches in series therewith, meanswhereby one of said switches is closed mechanically and the otherelectromagnetically upon an initial movement of said arm, and a normallyopen circuit closing device in connection with said arm for controlli-ngone ot said switches.

T. A starting rheostat comprising` a resistance varying` arm, aplurality of independently actuated switches iii-series therewith, meansfor closingsaid switches upon an initial movement of said arm, meanswhereby said switches are opened upon theoccurrence of 11o-voltage andoverload conditions, respectively, and a normally open circuit closingdevice in connection with saidarm for controlling' one of said switches.

8. A`s`tartiug rheostat' comprising a resist-- ance varying arm, aswitch in. series' therewith, means for mechanically closing said switchby a movement ol said a1'ma second switch i'n the armature circuit, andan electromao'n'etic device for closing the sante arranged to beenergized upon the initial movement of said arm.

9. A startingn` rheost-at comprising a resistance varying arm, a switchin series therewith, means for mechanically closingl said switch by amovement of said arm, an Velec-I tromagnetic device for opening saidswitch upon the occurrence of overload conditions, 1.25 e second switchin thc armature circuit, and an elcctromamictic device responsive tono'- voltaeje conditions and arranged to be e11- ergizcd upon an initialmovement of said arm for closing said switch.v

` 10.5 A startlingrlieostat comprising a resistance viirying atm, avswitch in series theredevice. .p

1l'. A s'tartingrheostat comprising a rewith, means for mechanically.closing lsaid y switchV by -a movement of said arm, a second switch inthel armature circuitv, .an"e1ectro- .magnetic device for closing saidswitch arranged to/he energized upon an' initial movemeint of said.arin,` and 'a' normally o en circuit closing device'in connection withsaid arm for controlling said electromagnetic 'i sistance varying arm, aswitch in series thereswitch and arranged 'to thel initial movement ofsaid arm, and a norwith,l means for mechanically closing s aid switch bya; movement of said arm, anelectromngnetic device for opening said`switch upon the occurrence of overload conditions,-

nrmature circuit, an

a second switch inthe 'elect-romagnetlc device for closlng said beenergized upon mally open circuit closing device in connecupon theoccurrence of overload conditions,

of which is `tion withvsa-id arm for controlling said sec v ondelectromagnetic device.l

1Q.l A starting rheosta't comprising a re 2 sistance varying arm, aswitch in series there- With, means for mechanically closing said switchby a Vmovement of said arm, an electromagnetic devicefor opening saidswitch PAUL H. ZlhlMiEl Witnesses y j BENJAMIN B. HULL,

Humax Oniloln).

